Torque converters are commonly used as an interface between an internal combustion engine and a transmission having a number of automatically selectable gear ratios. Some torque converters include a so-called lockup clutch that is connected between the pump and turbine of the torque converter, and that is engaged under certain operating conditions to rigidly connect the pump and turbine together. It is desirable to manage accumulator effects that may occur when controlling engagement of the lockup clutch.